OMC Cobra UpperGearcase Lubricant?

[jdeitchler]

I had a bearing go bad on the Upper Gearcase of my '93 OMC Sterndrive.
I am putting the bearing back in and putting together and I had a question?

What is the way to lubricate the main top Gear in and OMC Sterndrive?
I can grease the Ujoints and fill the oil in the Lower Gearcase, but what about the Upper Gearcase?
Do you just grease up the bearings and drive gears good when you put it together and hope that lasts for ever?

Let me know your thoughts

 

[Gary H NC]

Re: OMC Cobra UpperGearcase Lubricant?

The upper bearings and gears should be submersed in gear lube if its filled correctly.
No grease goes in the gear case at all...its all oil bathed.

 

[jdeitchler]

Re: OMC Cobra UpperGearcase Lubricant?

The Upper Gearcase on a 93 OMC Sterndrive has a main Gear that transfers power down to the lower unit.
It is held into place by two roller bearings on the shaft attached to the Gear.
Are those Roller bearings Oil Tight?
I don't believe is gets any Oil from the Lower unit.

Can I fill up the the 4 inch by 4 inch space with gear oil, like what is used in the lower unit?

There was no oil in the top of the Upper Gearcase when I disassembled it.

 

[Gary H NC]

Re: OMC Cobra UpperGearcase Lubricant?

Is this what the upper gear case looks like on yours?
I think the 1986 to 1993 were about the same..

 

[HT32BSX115]

Re: OMC Cobra UpperGearcase Lubricant?

There was no oil in the top of the Upper Gearcase when I disassembled it.

And you're wondering why they were damaged?

Whomever added oil when it was serviced (if it was ever serviced) either didn't add enough, didn't do it correctly, Or it leaked out.

Those gears and bearings are submerged in oil in a properly filled Cobra.


Cheers,


Rick

 

[jdeitchler]

Re: OMC Cobra UpperGearcase Lubricant?

That is exactly what it looks like.....

That is correct, there was no oil sitting in the cavity when I dissassembled it.

So I assume that once it is reassembled it will be Oil Tight?

And how much oil do I need to add, 1/2 full, 3/4 full?

- sorry for being such a nooby..

- any other gotcha's to look out for when reassembling the Upper and Lower Unit, or puting transom back on

 

[Gary H NC]

Re: OMC Cobra UpperGearcase Lubricant?

Then it has the dipstick that unscrews in the center of the top cover...or it should have.

You fill it from the center hole on the drive with the dipstick just resting on the threads.When it shows full on the stick thats it.Screw it in.

Be sure to replace the big O-ring on that top cover and use all new plastic washers on the drain,fill and dipstick plugs...

If this is a 4.3 engine the drive will take 64 ounces of lube.

 

[jdeitchler]

Re: OMC Cobra UpperGearcase Lubricant?

There is no dipstick on the Center Screw on the Cap, just a big filler screw?

This is a '93 OMC 4.3 with Cobra Sterndrive.

Is there a way that this gets oil sent up from the lower unit somehow?
- or is this upper gear compartment lubricated only by it's own oil?

 

[bruceb58]

Re: OMC Cobra UpperGearcase Lubricant?

It's all the same oil cavity. There should be a short dipsticl on the ned of the plug. If you don't have that, you need to get it.

 

[boatguya1]

Re: OMC Cobra UpperGearcase Lubricant?

The "big filler screw" is supposed to be a dipstick. It is all one oil cavity from lower to upper. Please read the propper manual on this or you will be doing it again. You should also pressure and vacume test the drive when it is re-assembled.

James

 

[boatguya1]

Re: OMC Cobra UpperGearcase Lubricant?

Haven't built a cobra upper in a while, will his replacing that brg require re-shimming? I'm home today with no manuals.

James

 

[HT32BSX115]

Re: OMC Cobra UpperGearcase Lubricant?

Haven't built a cobra upper in a while, will his replacing that brg require re-shimming? I'm home today with no manuals.

James

I think they need to be shimmed and the preload set when it goes back together.

If it's a 92/93 model it's probably a Dog instead of a Cone

 

[jdeitchler]

Re: OMC Cobra UpperGearcase Lubricant?

"It is all one oil cavity from lower to upper."

Is this correct. There is 1 foot plus of room from the upper 4 inch by 4 inch gear box on the Upper end to the Lower Unit with a ton of space in between.

I cannot believe this is all be one OIL well.

There has to be Oil for the top Gear box and the lower unit seems to be totally seperate of any oil lines, etc when I split them appart. No Oil was lost when I split the upper and lower cases.

Can the Guy with the Picture that matches my gearcase respond. It should be very similar...

 

[Don S]

Re: OMC Cobra UpperGearcase Lubricant?

I cannot believe this is all be one OIL well.

Well you better be believing it, because it's true. The drive holds approximately 62 Oz. of Gear lube.
There may not be hoses, but there are oil passages between the upper and lower.
You REALLY need to get a service manual, or you will be doing this again if you fill it wrong.
Head up the the Adults Only sticky, there are links to aftermarket service manuals for the OMC Cobra drive, but it's better than what you have now.

 

[Gary H NC]

Re: OMC Cobra UpperGearcase Lubricant?

This is the manual you really need,
http://cgi.ebay.com/ebaymotors/1993...e?hash=item19a375e532&_trksid=p4506.m20.l1116

Here is the dipstick,
http://www.wholesalemarine.com/pc/G...rive+System/Dipstick+For+Top+Cover+Cobra.html

You will really need the manual! The bearings do need shimmed to specs or you will be rebuilding it again..
And YES it is all one oil filled drive when put together..The manual will tell you the correct way to fill it.
Many Cobra drives have been toasted from someone filling the gear lube the wrong way..

 

[boatguya1]

Re: OMC Cobra UpperGearcase Lubricant?

Pay attention to what you are told in this thread. You have most likely over a hundred years of combined boat repair experience all telling you the same thing about your outdrive.

James

 

[a70eliminator]

Re: OMC Cobra UpperGearcase Lubricant?

The upper to lower connecting driveshaft has the oil galley, it's like a rifle barrel, that is how the oil passes between upper and lower.

 

[tagolf2000]

Re: OMC Cobra UpperGearcase Lubricant?

yes def listen to the advise here. my friend did the same thing u have done and jus filled it from the bottom til it came out the center screw. and then added some from the center screw but not nearly enough. needless to say me and him were stranded on the lake in no less than an hour on the lake. lol wasnt good and cost plenty to fix. fill from the center til it shows oil on the dipstick where it should. i was told by his mechanic not to over fill either because it would push seals out and cause it to leak oil

 

[Gary H NC]

Re: OMC Cobra UpperGearcase Lubricant?

We gave him the best advice and the links for the manual to do it right,Hope it all works out.
It would be a shame to end up redoing it in a month or so....

 

[jdeitchler]

Re: OMC Cobra UpperGearcase Lubricant?

Ok, read the manual and found out that the OIL filler tube that connects the Lower and Upper gearcases.

I was sold 2 quarts of gear oil (32 oz) and was told I only need to pump in about a quart to the lower air breather hole. So after adding a quart of gear oil I put everything back and test drove the boat on the water for 1/2 hour which took out the upper bearing.

Now understanding a little more about the amount of Oil and where to add it and check it. I am beginning to put the bearing back in putting back together and adding the correct amount of OIL.

What the heck is shimming. I have not found it in the manuals yet? I have the new bearings, but what is the correct procedure how to shim them? Or should a person not attempt it?

Any thoughts would be helpfull